I am assuming that this is an AIX system and I believe I had a similar
issue previously...
Anyway, consider the following:
Do an:
# lppchk -v
If no packages relevant to the mksysb command come back as broken move on.
Otherwise, fix broken packages.
Then rename the /image.data file to keep a backup of the original and then
run the mksysb command again. A new /image.data is created when mksysb is
run and the file does not exist.
Let me know if your Seg Fault goes away....
Anyway, worth every penny it cost ;^)......
Brian